On Wednesday, NASA’s unmanned Mars rover Curiosity passed another milestone. Having traversed 358 feet (109 m), the 4X4-sized, nuclear-powered explorer is one-quarter of the way from Bradbury landing to it’s first major destination, Glenelg. Now that Curiosity’s mobility system has had the bugs shaken out of it, it’s the arm’s turn to take center stage. Curiosity will spend the next six to ten days testing its seven-foot (2.1 m) arm and the set of tools that make up its “hand.”
"We will be putting the arm through a range of motions and placing it at important 'teach points' that were established during Earth testing, such as the positions for putting sample material into the inlet ports for analytical instruments," said Daniel Limonadi, lead systems engineer for Curiosity's surface sampling and science system. "These activities are important to get a better understanding for how the arm functions after the long cruise to Mars and in the different temperature and gravity of Mars, compared to earlier testing on Earth."
The tests require a flat area with the sun at a particular angle. This is the reason for Curiosity’s stopping where it has. Tests will not only include rehearsing the arm’s movements, but the calibration of its Mars Hand Lens Imager and the Canadian-built Alpha Particle X-Ray Spectrometer.
"We're still learning how to use the rover. It's such a complex machine – the learning curve is steep," said JPL's Joy Crisp, deputy project scientist for the Mars Science Laboratory Project, which built and operates Curiosity.
Curiosity landed on Mars in Gale Crater on August 6 at an area now designated Bradbury Landing. After a three-week shakedown, the mobile science lab took its first drive, streamed a human voice back to Earth and fired its laser.
Once the arm tests are completed, Curiosity will spend the next few weeks inching toward Glenelg at 1.5 inches (4 cm) per second as the first leg of its two-year mission to seek out areas where life may have, or still does exist on Mars.
Built by the Space Division of MDA Information Systems Inc. of Pasadena California, Curiosity’s arm has five degrees of movement and is strong enough to lift its 73-pound (33 kg) hand. The hand is equipped with an array of tools and instruments, including a drill, an alpha-particle spectrometer, a digital magnifier, sample collector and a brush for removing dust from sample areas.